Human bone marrow contains a subset of quiescent early memory CD8(+) T cells characterized by high CD127 expression and efflux capacity.

Even today it is still not completely understood how CD8(+) T-cell memory is maintained long term. Since bone marrow (BM) is a niche for immunological memory, we sought to identify long-lasting early memory CD8(+) T cells in this compartment. To achieve this, we looked for CD8(+) T cells that are able to efflux Rhodamine 123, a typical property of stem cells.